PolygonIntersectionAnalyzer.h

/**********************************************************************
 *
 * GEOS - Geometry Engine Open Source
 * http://geos.osgeo.org
 *
 * Copyright (C) 2021 Paul Ramsey <pramsey@cleverelephant.ca>
 * Copyright (C) 2021 Martin Davis
 *
 * This is free software; you can redistribute and/or modify it under
 * the terms of the GNU Lesser General Public Licence as published
 * by the Free Software Foundation.
 * See the COPYING file for more information.
 *
 **********************************************************************/
 
#pragma once
 
#include <geos/geom/Coordinate.h>
#include <geos/noding/SegmentIntersector.h>
#include <geos/algorithm/LineIntersector.h>
#include <geos/operation/valid/TopologyValidationError.h>
 
 
#include <geos/export.h>
 
// Forward declarations
namespace geos {
namespace noding {
class SegmentString;
}
}
 
namespace geos {      // geos.
namespace operation { // geos.operation
namespace valid {     // geos.operation.valid
 
class GEOS_DLL PolygonIntersectionAnalyzer : public noding::SegmentIntersector {
    using CoordinateXY = geos::geom::CoordinateXY;
    using SegmentString = geos::noding::SegmentString;
 
private:
 
    algorithm::LineIntersector li;
    bool m_hasDoubleTouch = false;
    bool isInvertedRingValid = false;
    int invalidCode = TopologyValidationError::oNoInvalidIntersection;
    CoordinateXY invalidLocation;
    CoordinateXY doubleTouchLocation;
 
    int findInvalidIntersection(
        const SegmentString* ss0, std::size_t segIndex0,
        const SegmentString* ss1, std::size_t segIndex1);
 
    static bool addDoubleTouch(
        const SegmentString* ss0, const SegmentString* ss1,
        const CoordinateXY& intPt);
 
    void addSelfTouch(
        const SegmentString* ss, const CoordinateXY& intPt,
        const CoordinateXY* e00, const CoordinateXY* e01,
        const CoordinateXY* e10, const CoordinateXY* e11);
 
    static const CoordinateXY& prevCoordinateInRing(
        const SegmentString* ringSS, std::size_t segIndex);
 
    static bool isAdjacentInRing(const SegmentString* ringSS,
        std::size_t segIndex0, std::size_t segIndex1);
 
 
public:
 
    PolygonIntersectionAnalyzer(bool p_isInvertedRingValid)
        : isInvertedRingValid(p_isInvertedRingValid)
        , invalidLocation(CoordinateXY::getNull())
        , doubleTouchLocation(CoordinateXY::getNull())
        {}
 
    void processIntersections(
        SegmentString* ss0, std::size_t segIndex0,
        SegmentString* ss1, std::size_t segIndex1) override;
 
    bool isDone() const override {
        return isInvalid() || m_hasDoubleTouch;
    };
 
    bool isInvalid() const
    {
        return invalidCode >= 0;
    };
 
    int getInvalidCode() const
    {
        return invalidCode;
    };
 
    const CoordinateXY& getInvalidLocation() const
    {
        return invalidLocation;
    };
 
    bool hasDoubleTouch() const
    {
        return m_hasDoubleTouch;
    };
 
    const CoordinateXY& getDoubleTouchLocation() const
    {
        return doubleTouchLocation;
    };
 
};
 
 
} // namespace geos.operation.valid
} // namespace geos.operation
} // namespace geos